70 terms

# Quantum Theory

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Democritus
First coined the term 'atoms'
Einstein
Explained the "photoelectric effect" by proposing that light is both a wave and a particle
Planck
proposed that atoms accept ONLY specific amounts of energy called quanta
Dalton
proposed that all matter is made up of atoms and established ideas about how atoms combine to form compounds in definite proportions.
Bohr
proposed that electrons orbit the nucleus in circular orbits (solar system model)
Thomson
positive and negative charges make up his plum pudding model.
Millikan
determined the mass to charge ratio of an electron
Rutherford
discovered the nucleus
Photoelectric Effect
uses stopping voltage to determine the energy of electrons, and enabled Planck's constant to directly relate frequency to energy.
increases
As energy increases, frequency______?
Red
Which has lower energy? Red of Violet?
Wavelength
Distance between corresponding points on adjacent waves. Length of one complete wave.
Frequency
number of waves that pass a point during a certain time period. Defined as the number of waves that pass a given point in a specific time (1 second)
Amplitude
distance from the origin to the trough or crest.
Quanta
energy that is emitted in small specific amounts.
Photoelectric Effect
the emission of electrons from a metal when light shines on a metal.
Frequency+wavelength formula
C=λv
Inversely
Frequency+wavelength are_____proportional.
Higher
Low energy waves have _____ frequencies.
Length of visible spectrum
400nm-700nm
Violet
Which has higher energy? Red or Violet?
Photon
bundles of light energy that is emitted by electrons as they go from higher energy levels to lower energy levels. Particle of electromagnetic radiation having zero mass and carrying a quantum of energy.
Each element has a unique bright-line emission spectrum
What is the significance of the Line Emission Spectrum?
Proportional
Energy of a photon is ______ to its frequency.
Energy+Frequency Formula
E=hv
Energy+wavelength Formula
E=hc/λ
Hertz (Hz)
what is frequency measured in?
Joules (J)
what is energy measured in?
meters, nm, etc
what is wavelength measured in?
Planck's constant
6.6262*10^34 J.s
C=speed of light
3.00*10^8
Orbital
region in space where there is 90% probability of finding an electron. "electron cloud"
Two
Each orbital can hold___electrons
Two
The S sublevel has____electrons
One
The S sublevel has___orbitals
Three
The P sublevel has______orbitals
Six
The P sublevel has_____electrons
Five
The D sublevel has____orbitals
Ten
The D sublevel has____electrons
Photon
When the electrons falls to a lower energy level, a _____ is emitted.
Size of the orbital
What does the energy level tell you?
Aufbau Principle
electrons fill the lowest energy orbitals first. An electron occupies the lowest-energy orbital that can receive it.
Pauli's Exclusion Principle
Each orbital can hold TWO electrons, but they must have opposite spins.
Hund's Rule
Within a sublevel,place one electron per orbital before pairing them up. "urinal analogy"
Ground State
lowest energy state of an atom
Excited State
a state in which an atom has a higher potential energy that it has in its ground state.
Principle quantum number
symbolized by n, indicates the main energy level occupied by the electron.
Angular momentum number
symbolized by l, indicates the shape of the orbital
s-spherical
p-dumbbell
Magnetic quantum number
symbolized by m, indicates the orientation of an orbital around the nucleus.
Spin quantum number
has only two possible values (+1/2, or -1/2) which indicate the two fundamental spin states of an electron in an orbital
Higher
As the wavelenght become shorter, the energy is______.
Bohr Model
electrons orbit the nucleus in circular paths of fixed energy.
Quantum Numbers
specify the "address" of each electron in an atom
S-orbitals
electrons are found within a sphere around the nucleus
D-orbitals
most appear to be the combination of two p-orbitals, "daisy"
P-orbital
orbital that look like "dumbbells or propellers" or tear drops.
F-orbitals
really complicating structure.
n
# of sublevels per level
n^2
# of orbitals per level
Dalton
All atoms of the same element are identical, other atoms are different. Proposed that atoms are small, uniformely dense, and indivisible.
Crooke & Thomson
used a cathode ray tube. Determined that atoms also contain witin themselves small negatively charged particles. They discovered the electron, the 'first' subatomic particle.
Rutherford
He tested Thomson's model with the gold foil experiment. According to Thomson's model, radiation particles should not be deflected. but in his experiment, some radiation was deflected.
Discovered the neutron. He reevaluates data and proposes that the radiation was actually a "massive" particle.
Planck
will only accept energy in small 'quantized' packets.
Broglie
Applied wave-particle theory to electrons. Found that electrons exhibit wave properties.
Schrodinger
The wavefunction helps describes the location of the electron, and its probable location. Electrons have a wavelenght.
Ion electron configuration
write the electron configuration for the closest Noble Gas
Ion formation
Atoms gain or lose electrons to become more stable.
Heisenberg Uncertainty Principle
impossible to know both the velocity and position of an electron at the same time.
Pauli Exclusion Principle
no to electrons in an atom can have the same 4 quantum numbers.